About this world
HIP 19976 b is a Neptune-like planet orbiting HIP 19976, an orange dwarf 131 light-years from Earth. It is about 4.9 times the size of Earth (its size estimated from its mass), with at least 22 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 50.7 days at 0.23 AU from its star, closer than Mercury is to the Sun, on a strongly elongated orbit (e = 0.3).
Its equilibrium temperature is about 378 K (105 °C): too cold for liquid water on its surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2022 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum.